Pressure cooker



Aug. 26, 1952 M. KELLERv .2,608,318

PRESSURE COOKER Filed Oct. 22. 1949 2 SHEETS-SHEET 1 Aug. 26, 1952 FiledOct. 22, 1949 figa M. KELLER PRESSURE cooKER 2 SI'IEETS--SI-IEET 2 f Zfy/ /'4////// l 7 /7g.7 1 /0 /8 Y /M f ff3 a satented Aug. 26, 1952UNITED STATES PATENT oEElcE Application October 22, 1949, Serial No.122,904

In Switzerland November 26, 1948 8 (Jlaims.` (Cl. 220-40) with a sealingmeans in the form or a packing` ring. .f

rlhe invention consists in the fact that the pot has one or more edgedepressions or wall perforations and the packing ring is so formed that.on putting the lid on the pot, the interior of the latter communicateswith the atmosphere and this communication is maintained during therotation of the lid into the locking position until immediately beforeit reaches the latter position and'that, on rotating the lid from thelocking position into the position of release, the com munication is`established before it reaches the latter position.`

"Ihree embodiments of `the pressure cooker according to the inventionare represented by way of example by the accompanying drawings,

' of which Fig." lV is a verticalsection through a part of a pressurecooker according to the rst embodiment, showing the lid in the lockedposition;

Fig. 2` is the same vertical section, but showing the lid unlocked;

Fig. 3 is a section on the line III- III of Fig. 2;

Fig. 4 is a section on the line IV-IV of Fig. l;

Fig. 5 is a vertical section through a part of a pressure cookeraccording to the second embodiment; f

Fig.` 6 is a section on the line VI-VI of Fig. 5;

Fig'. 7 is a vertical section through a part of a pressure cookerVaccording to the third embodiment; and f Fig. 8 is a section on theline VIII-VIII of Fig. 7.

l denotes the lid which is used for closing the pot 2 and on which asafety valve (not shown) is arranged. The pot 2 has, on its open end, a'conical surface 3 which widens towards the edge ofthe pot and serves asa sealing surface and it also has, on its open end, a flange withrecesses which serve for the formation of a number of segments 4. Thelid l is placed over the edgeof the pot and bears, at its overlap, anumber of locking teeth 5 which, on the rotation of the lidthat is puton the pot, are moved to below the segments 4. The lid l has, on itsinside, a groove 1 which serves for receiving a packing ring B.

The packing ring 8, according to the embodiment shown in Fig. 1, is madeslightly conical at the part that is yto be forced into the groove 1.

in order that it should not drop out of the groove "I.. However, it mayhave a uniform thickness 2 throughout all the part that lies Within thegroove. In order that, in such a case, the packing ring should not dropout of the groove, it may have a ledge-shaped orrib-shaped projectionthat is to be inserted in a second groove or rabbet (Fig. 2) or it maybeclamped by means ol an open spring ring 9 inserted in the groove 1 ofthe lid. Y

The part of the packing ring 8 that projects beyond the groove lies on aconical surface `l0 or' the lid, which surface serves as a sealingsurface. The angle of inclination, which the conical surface it oi' thelid makes with the verticai, is smaller than the angle which thelconicalsurface of the pot makes with the vertical. uIn addition, thediameterof thepacking r1ng`8 at its free edgeis smaller than thediameter of the conical surface 3 at the' open` endof the jpot.

lConsequently, When the `lid is put on the pot,

theY packing ring is pushed. without resistance and without deformation,intothe latter, its `edge lying on the conical surface 3. In thisposition, the packing ring 8, under the weight of the lid, alreadyenects complete sealing. In order to lock the'lid on the pot, the formeris rotated from its pressure la or lo until thehandle" ll of the lid islocated above the handle l2 of the pot and the locking teeth 5 liecompletelybeneath the segments li.'

The edge of the pot 2 is provided with an edge depression I3 (Figs. 2, 3and 4) instead of which a perforation lli (Figs. 5 and 6) of any desiredshape could be provided. The packing ring 8 has an edge recess l5 or,instead. a lslot ll. In order that the packing ringil should also eiectsealing at the part provided with the edge recess l5 or the slot il, anedge reinforcement in the form of a bead or the like is necessary onaccount of the different angles of inclination o1" the two sealingsurfaces 3 and i0. The edge depression I3, or, instead, the perforationI4, and the edge recess i5, or, instead, the slot l1, occupy `suchpositions that, when the lid is put on the pot with its handle Il in theposition Ia shown in Fig. 3, the inside of the pot communicates with theatmosphere. This communication is maintained on rotating the handle Ilof the lid in the direction towards the handle l2 of the pot until ithas reached approximately the position Ib, and is then interrupted onrotating the lid further into the position in which the handle ofthelidlies above the handle of the pot. In this last mentioned position,which corresponds to the locking position of the lid, the locking teeth5 lie,v comaeoasis of pressure can be obtained only after rotation ofthe lid into the locking position has beencar`Vv red out and,conversely, that, on rotatingV the lid into the releasing position, anSqllalifap ,0i

pressure is possible before the latterv position reached, i. e., beforethe release-of the locking teeth 5 by the segments 4 takes place, sothat a `3 slipping off of the lid is impossible. At the. same time, inorder to prevent accidents, the sudden escapelof large quantities offrothing material bei,V Yc ookedis rendered impossible.

',IT'h'egwsamefresult can lbe obtaine'dfwith edge recesses I5 on thevpacking ring 8 or with'slots Il ifgth packingring 3 shorter and itsfreeedge ,lies on a oirN of the conical surface 3 of the pct, ,whichpac ngring is located above the bottom edge of the edge depression I3 on Atheedge ofthe pot, as shown in Figs. 'l and 8. "For sealingdtheedgedepression I3, thepacking ring 8 is, inthis case, provided with alugSa which is placed lin frontl of Vthefedge depression I3 whenthe lidis rotated into the locking position and the handle Iv-I, of the lidcomes to'lie above the handle I2 of thepot. IoIfther/e are a pluralityof edge recesses on thev pot,v a corresponding number of lugs 8a I,nrojectingv beyondl the free end are to be provided on thepackigrin'gmil. Such fa" packing ring 3 provided with flugs 8.aV Ycanalso be used as a 4sealing means when the pot is provided with perf',ationsll in the'vv'all instead of with the edge depressions I3.

slt Vhas been found to be advantageous to prolvide two edge recesses i5or slots Il on the packing ring B, 'in order that one or the other of,ythe ftwo should be veffective vaccording to whetherthe lid is rotatedfrom the locking posi- 4tion to' the position Ia or'Ic of the handle ofthe lid or vice versa. However, two or more edge Kdepressions I3 orperforations I4 in the pot and a vcorre'spondi'n''g number of edgerecesses l5 or 'slots I'I fmay bey provided on theVV packing ring 8.Thev edge depressions I3 or perforations'lll, -on the one hand, and theedge recesses I5 or slots Il, onv the other, which could also b'eprovided on pots Without aeconical sealing surfacel, constitutela safetymeans which is additional to the safety valve already provided on thelid, since, one rotating the lid into the unlocking position, they bringabout an equalisation of pressure if, owing to an oversight, ithas notalready been brought about by openingthe safety valve. lf, for anyreason, the safety valve'should fail when a particularpressure isreached withinA the pot,n a rise in pressure above the permissiblemaximum pressure effects la-deformation-of the partiof the packing ringv8 that covers :the edge depression I3-or the wall perforation I4. 'Iheresult of This effect vis-also producedif thereare more than one edge.depression AI 3 or. wall Vperforation .14. The arrangementr of edgedepressions `and .or

wall perforationson -the pot and of .edge recesses or slots on thepacking ring consequently consti- 4ing contact with `the inner; surfa eYto vleave at least one Vperforation in tlie.

Ainthe region of said rim; .adetac `faultless and secure sealing isensured at internal ypressures of any desired magnitude.

In the kexamples of embodiment described, the

vrp otzlias aconical sealing surface 3 which widens vtowards the edge ofthe pot and instead of which a curved surface I9 could be provided, asshown `in Fig.' 7'.' Since, in such a case, the pot has, at

tso'pening, a greater diameter than that of the packing ring at its freeedge, the lid can also. without resistance and without 4deformationofthe 'packing `4ring belput' on the 'p'o't -l`and "rotated into thelocking. position.

lvvhatriairn'is':,. l 1. A pressure eok'r, `cbx`p`ris1`ng`c`om tion,`apotohaving a rim andat least one r in theregion of said" iin; "d'eta"liable, lid ont@ therme Q ffsdpf tegral with the rviiifroffsa` 1 means,integral, With fefeig'e, f adapted to engage said 'rstlc Y ktotigntlyseouresaid-e1i'd to sai termine@ poitign, .and i9. (release.Santa .is .turned fieriaiirdtrn" either .1i.m= =tion7:.4 en@ anannulrfling ,secured tothe. inner .sgrfacafsaidlfd' P jecting downwardlyinside of andl ad aceri ,to saidgrim of said, kpotH- soasvto 'lateralsealinscontat with the inner. Surf O f am i201; adjacent to Said. Him. nsaid, l'i. SQS'LG'u "60 said pot by said locking means, said'sealingmember. having at. least ongree heine shape'djbf-s to leave atr leastoneirecess in the regionofthe rim Y of Ysani pot .uncovered.. while...saisi 1 ne means. are, notfully engaged, and havinglsealins portionsclosing at least one recess when'fsaid locking means arelfullyengagd,....7. 2. A pressure cookermcomprlsng @Qmbiri'ation,.a p01; having a rimand kat least one pe a- -tion in the region.of 'said rim:,.a,detachablcllid tting onto the rim of said pot; first locking meansintegrall with Htherim .of said pot second locking means.mtegralwiththeedgey of said lid, and adaptedtoengage saidrsl. locking me, ,M as totightly secure said lid to said pot ina pr etermined position, and to,Ilease said lid, n L said lid is turned for a predetermined anglenineither. direction.; andan ,annular sealing .member securedto the innersurfaceofsaidLl s' jecting downwardly e inside o fiand,adja` nt [to saidrim of said pot Vso. aSVGQbe in ,lateral Y adjacentl to said, rim whensaid llid is said pot by saidlooking,meanssaid seY g .ber having atleastgne leQeS/Sfbrlg She ed ofthe rim of ,saiqcpot unoyeredwhn saidif;- ing meanscarfe not fully engaged, ancllaJ fig ing DQltionsclosingatleast oefperibratin'w en Said locking means are falli/Zehe ged...1 r3. A pressure cooker comprfismf 'f tion,v aA pot having-arimLandfatlea o means integral with`tlie` edge" f said lid,V arid y adapted to`engagesaid `firstflockingmeans so as to tightly secure said lid to saidpot in a predetermined position, and to release said lid when said lidis turned for a predetermined angle in either direction; and anannularsealing member secured to the inner surfaceof said lid and projectingdownwardly inside of and adjacent to said rim of said pot so as to be inlateral sealing contact with theinner suriace of said pot adjacent tosaidrim when saidilidyis secured to said pot b y said locking means,said sealing memberhaving at least one slot being shaped so as to leaveat least one recess in the region of the rim of said pot uncovered whilesaidlocking means are not fully engaged, and having sealing portionsclosing at least one recess when said locking means are fully engaged.

4. A pressure cooker comprising in combination, a pot having a rim andat least one perforation in the region of said rim; a detachable lidtting onto the rim of said pot; rst locking means integral with the rimof said pot; second locking means integral with the edge of said lid,and adapted to engage said iirst locking means so as to tightly securesaid lid to said pot in a predetermined position, and to release saidlid when said lid is turned for a predetermined angle in eitherdirection; and an annular sealing member secured to the inner surface ofsaid lid and projecting downwardly inside of and adjacent to said rim ofsaid pot so as to be in lateral sealing contact with the inner surfaceof said pot adjacent to said rim when said lid is secured to said pot bysaid locking means, said sealing member having at least one slot beingshaped so as to leave at least one perforation in the region of the rimof said pot uncovered lwhile said locking means are not fully engaged,and having sealing portions closing at least one perforation when saidlocking means are fully engaged.

5. A pressure cooker comprising in combination, a pot having a rim andat least one recess in the region of said rim, the inner surface of saidpot adjacent to said rim having a portion widening upwardly andoutwardly, and extending from immediately below said recesses to the rimof said pot; a detachable lid fitting onto the rim of said pot; firstlocking means integral with the rim of said pot; second locking meansintegral with the edge of said lid, and adapted to engage said firstlocking means so as to tightly secure said lid to said pot in apredetermined position, and to release said lid when said lid is turnedfor a predetermined angle in either direction; and an annular sealingmember secured to the inner surface of said lid and projectingdownwardly inside of and adjacent to said rim of said pot so as to be inlateral sealing contact with the inner surface of said pot adjacent tosaid rim when said lid is secured to said pot by said locking means,said sealing member having at least one recess, being shaped so as toleave said recesses in the region of the rim of said pot uncovered whilesaid locking means are not fully engaged, and having sealing portionsclosing said recesses when said locking means are fully engaged, andadapted to uncover portions of said recesses by elastically expandingwhen a predetermined maximum pressure is exceeded.

6. A pressure cooker comprising in combination, a pot having a rim andat least one perforation in the region of said rim, the inner surface ofsaid pot adjacent to said rim having a portion widening upwardly andoutwardly, and extending from immediately below said perforations to theintegral with the edge of said lid, and adapted to engage said firstlocking means so as toutightly secure saidl lidito saidpotin`aupredetermined position,and to release said lid when said ,lid isturned for a predetermined `angle in either direction; and an annularsealing member securedtto the inner surface of said lid and projectingdownwardly inside of` and adjacent to said rim of said pot so as to' bein lateral sealing contact with the inner surface of said pot adjacentto said rim when said lid is secured to said pot by said locking means,said sealing member having at least one recess being shaped so as toleave said perforations in the region of the rim of said pot uncoveredwhile said locking means are not fully engaged, and having sealingportions closing said perforations when said locking means are fullyengaged, and adapted to uncover portions of said perforations byelastically expanding when a predetermined maximum pressure is exceeded.

7. A pressure cooker comprising in combination, a pot having a rim andat least one recess in the region oi' said rim, the inner surface ofsaid pot adjacent to said rim having a portion widening upwardly andoutwardly, and extending from immediately below said recesses to the rimof said pot; a detachable lid tting onto the rim of said pot; firstlocking means integral with the rim of said pot; second locking meansintegral with the edge of said lid, and adapted to engage said firstlocking means so as to tightly secure said lid to said pot in apredetermined position, and to release said lid when said lid is turnedfor a predetermined angle in either direction; and an annular sealingmember secured to the inner surface of said lid and projectingdownwardly inside of and adjacent to said rim of said pot so as to be inlateral sealing contact with the inner surface of said pot adjacent tosaid rim when said lid is secured to said pot by said locking means,said sealing member having at least one slot being shaped so as to leavesaid recesses in the region of the rim of said pot uncovered while saidlocking means are not fully engaged, and having sealing portions closingsaid recesses when said locking means are fully engaged, and adapted touncover portions of said recesses by elastically expanding when apredetermined maximum pressure is exceeded.

8. A pressure cooker comprising in combination, a pot having a rim andat least one perforation in the region of said rim, the inner surface ofsaid pot adjacent to said rim having a portion widening upwardly andoutwardly, and extending from immediately below said perforations to therim of said pot; a detachable lid fitting onto the rim of said pot;first locking means integral with the rim of said pot; second lockingmeans integral with the edge of said lid, and adapted to engage saidiirst locking means so as to tightly secure said lid to said pot in apredetermined position, and to release said lid when said lid is turnedfor a predetermined angle in either direction; and an annular sealingmember secured to the inner surface of said lid and projectingdownwardly inside of and adjacent to said rim of said pot so as to be inlateral sealing contact with the inner surface of said pot adjacent tosaid rim when said lid is secured to Said Dot by Said locking means,said sealingi member having at least one slot being shaped

